Arrow shafts, in general, are equipped with replaceable arrowheads. There are many reasons for this, not the least of which is to permit the ready replacement of a damaged arrowhead while an archer is in the field. More frequently, an archer is prompted to change arrowheads when he changes the type of shooting with which he is involved. Thus, the archer may have been shooting at straw targets or the like, using standard arrow points, and decide to mount hunting heads on each of his arrow shafts so that he might partake of the hunt.
Assuming that the archer has been having success using an arrow point of a given weight, he will, in all likelihood, install a hunting head of the same weight. Having done so, it may come as a surprise to the archer to find that the flight of the arrow is erratic; and, the accuracy he has gained in practice with the arrow point on his shaft is no longer in evidence when shooting with a hunting head.
Hunting heads (broadheads) are designed to cut, producing hemorrhaging in body. Hunting heads typically carry many different styles of cutting edges (razors), some fixed, some folding out of the hunting head ferrule body at impact. Although the heads differ in cutting configuration and design, they each have a means for coupling to the end of an arrow shaft. Typically, an existing hunting head has a threaded shaft protruding rearward from its end. The arrow has an internally threaded insert at it's forward end for receiving this threaded shaft. The threaded insert is commonly glued into the arrow shaft's leading end.
Typical arrow shafts are hollow in design. However, there are arrows used having shafts that are of solid construction, usually wood. Typical fittings are readily available to convert this type of arrow shaft to allow for threaded arrow points.
When inserted and rotated securely into the arrow insert, current hunting broad heads will terminate rotation at random radial positions; and, because of their length they increase the arrow's overall assembled length. The uncontrolled radial positioning of the broad head and the increased assembled length is undesirable.
In current, common practice, the archer wants to assemble his broadheaded arrow in a manner that maximizes cutting blade clearance on the bow and allow blade alignment with the flights on the arrow. In the prior art, this could only be achieved by successively installing many different hunting heads to a single arrow shaft hoping that one would couple at the correct radial position. Most commonly however, an archer, in frustration, will remove the arrow head and insert from the shaft and glue the assembly to the shaft in proper orientation. This marriage of the glued assembly to the arrow shaft to achieve correct radial alignment makes the arrow, insert and hunting head inseparable and dangerous to transport to the hunt location.
Although the overall weight of the arrow may not be changed by changing from arrow point to broadhead hunting point, the archer may not realize that the overall geometry of the arrow has been sufficiently changed to move the balance point and inpair the flight characteristics of the arrow to which he had become accustomed.
The balance point of the arrow is of critical importance. In tests of the accuracy of arrows, both actual and computer simulated testing, it has been shown that arrows are most accurate when they are seven to ten per cent (front of center) nose heavy. While many archers are familiar with this rule, they are limited as to where the balance point of their arrow will fall based on their selection of a particular broadhead hunting point. As is many times the case, the arrow's balance point will not be the same as when a practice arrow point was attached.
It is the objective of the present invention to enable an archer to exactly duplicate his arrow's finished length, weight, balance point and flight characteristics when changing from practice arrow points to broadhead hunting points, within the established standards set by the manufacturers of the various arrow shafts and devices. This will be accomplished by utilizing a broadhead hunting point that weighs the same (or approximately the same) as the practice arrow point, and, will duplicate the overall assembled length of the practice arrow when the invention disclosed herein is utilized. Another objective of the invention will allow the ready alignment of the arrow flights to the broadhead razors.